(a) Field of the Invention
This disclosure relates to a liquid crystal display.
(b) Description of the Related Art
A liquid crystal display is a type of flat panel display. A liquid crystal display includes two display panels on which field-generating electrodes, including a pixel electrode and common electrode, are disposed and a liquid crystal layer interposed between the display panels. In the liquid crystal display, a voltage is applied to the field-generating electrodes to generate an electric field across the liquid crystal layer, thereby controlling an alignment of liquid crystal molecules of the liquid crystal layer with the electric field. Accordingly, a polarization of incident light can be controlled, and an image displayed.
The liquid crystal display further includes a switching element electrically connected to the pixel electrode, and a plurality of signal lines, including a gate line and a data line, for applying a voltage to the pixel electrode by controlling the switching elements.
In a vertical alignment (VA) mode liquid crystal display, in which a director of the liquid crystal molecules stands vertically relative to a surface of the display panels when an electric field is not applied thereto, it is desirable to have a high contrast ratio and a wide reference viewing angle. A wide viewing angle is a viewing angle with a contrast ratio of 1:10, or an intergray luminance inversion limitation angle.
In the vertical alignment (VA) mode liquid crystal display, it can be desirable to make a lateral visibility approximate a frontal visibility. In order to make the lateral visibility approximate the frontal visibility, it has been proposed that one pixel be bisected into two sub-pixels, while different voltages are applied thereto to differentiate a light transmittance thereof from each other.
For example, bisected sub-pixels can be capacitor-combined with each other, and a voltage applied directly to one sub-pixel while a voltage drop induced by the capacitor combination reduces the voltage to the other sub-pixel, thereby differentiating the voltages applied to the two sub-pixels from each other so as to select a different light transmittance thereto. However, such a method may involve a loss in overall light transmittance because the voltages applied to each of the two sub-pixels are lowered. Alternatively, a number of the gate lines or the data lines may be increased to thereby apply a different voltage to each of the two sub-pixels. However, as the number of the gate lines or the data lines increases, an aperture ratio of the liquid crystal display is reduced.
Several attempts have been made to improve motion picture display quality in a liquid crystal display, including the development of high speed driving, for example. High speed driving can consume significant power because of the rapid frame speed, and hence a column inversion driving mode has been introduced to reduce power consumption.
However, with the column inversion driving mode, when a relatively high gray box is displayed on a relatively low gray ground screen, vertical crosstalk may occur at the top and the bottom of the box with a different gray from that of the ground screen. Furthermore, when data voltages with the same polarity are applied in a vertical direction, and pixel voltages with positive and negative polarities differ from each other, flicker may be generated.
Accordingly, a liquid crystal display with improved lateral visibility, improved display quality, and high speed driving would be desirable.